Print version ISSN 0034-7094
Rev. Bras. Anestesiol. vol.58 no.5 Campinas Sept./Oct. 2008
Ultrasound-guided sciatic-femoral block for revision of the amputation stump. Case report*
Bloqueo isquiático-femoral guiado por ultrasonido para revisión de muñón de amputación. Relato de caso
Pablo Escovedo Helayel, TSAI; Diogo Bruggemann da ConceiçãoII; Carla FeixIII; Gustavo Luchi BoosII; Bruno Schroder NascimentoIII; Getúlio Rodrigues de Oliveira Filho, TSAIV
Co-Responsável do CET/SBA Integrado de Anestesiologia da SES-SC, Coordenador
e Pesquisador do NEPAR
IIAnestesiologista; Pesquisador do NEPAR do CET/SBA Integrado de Anestesiologia da SES-SC
IVAnestesiologista, Doutor em Anestesiologia; Responsável do CET/SBA Integrado de Anestesiologia da SES-SC, Pesquisador do NEPAR
OBJECTIVES: The use of ultrasound in regional blocks has become increasingly
used because its role as a facilitator and its efficacy. Direct ultrasound visualization
allows the identification of peripheral nerves, independently of the ability
of obtaining sensitive or motor stimulation.
CASE REPORT: This is the case of a patient who underwent revision of the amputation stump at the knee under ultrasound-guided sciatic-femoral block with 40 mL of 0.5% ropivacaine, promoting complete sensitive blockade and excellent surgical anesthesia.
CONCLUSIONS: Ultrasound assistance is capable of amplifying the spectrum of uses of peripheral nerve blocks in surgical interventions on amputated limbs in situations neurostimulation cannot be used.
Key Words: ANESTHESIA, Regional; ANESTHETIC TECHNIQUE, Regional: sciatic, femoral block; EQUIPMENT, Ultrasound.
Y OBJETIVOS: El uso del ultrasonido en la anestesia regional se ha venido
convirtiendo cada vez más en algo muy difundido por su rol de facilitador
y por su eficacia. La visualización directa a través del ultrasonido
permite que se identifiquen los nervios periféricos, independientemente
de la capacidad de poder obtenerse una estimulación sensitiva o motora.
RELATO DEL CASO: Paciente sometido a revisión de muñón de amputación al nivel de la rodilla bajo bloqueo isquiático-femoral guiado por ultrasonido con 40 mL de ropivacaína a 0,5%, promoviendo bloqueo sensitivo completo y anestesia quirúrgica de excelente calidad.
CONCLUSIONES: La asistencia ultra sonográfica es capaz de ampliar el espectro de utilización de los bloqueos periféricos en las intervenciones quirúrgicas sobre miembros amputados en situaciones en que la neuro estimulación no puede ser utilizada.
In some clinical circumstances, such as the amputation of the distal extremity of a limb, adequate motor or sensitive responses for nerve identification is not feasible. Direct ultrasound visualization allows to approximate the tip of the needle to the peripheral nerve within real-time detection, therefore allowing its blockade. Besides, one can monitor the dispersion of the local anesthetic and the presence of anatomical variations, ensuring high rates of success of regional blocks 1-3. Unlike neurostimulation and paresthesia techniques, the ultrasound does not depend on sensitive or motor responses to perform regional blocks.
Amputation of a limb can trigger the development of chronic neuropathic pain in which the efficacy of the medical treatment is increased by the blockade of the peripheral nerve conduction 4. Besides, those patients frequently undergo surgeries to clean the amputation stump. Thus, ultrasound guidance can be the only technique available for peripheral blocks in the treatment of chronic neuropathic pain or surgeries in the amputation stump.
This is the case of a 23-year old male patient, weighing 80 kg, 1.65-m tall, physical status ASA II, who was involved in a car accident 5 months before the current admission, with traumatic amputation of the right leg at the knee. From then on, he developed chronic pain in the amputation stump, being medicated with amytriptiline and carbamazepine daily, with partial control of the pain. Due to signs of tissue devitalization on the amputation extremity, he returned for elective surgery for revision of the stump.
After venipuncture, monitoring with non-invasive blood pressure, electrocardioscopy, and pulse oximeter was instituted, and the patient was sedated with 3 mg of intravenous midazolam. Sciatic and femoral nerve blocks were performed with the help of the ultrasound (Sonoace 8000SE®, Medison, South Korea) with a wide-band linear transducer (5 - 10 MHz) covered with a sterile plastic adhesive on the surface that gets in contact with the skin. The femoral nerve block was done using a transversal ultrasound image of the inguinal region, 1 cm below the inguinal ligament. A 5-cm long 22G isolated needle (Stimuplex A50®, B.Braum, Germany) was introduced longitudinally to the ultrasound beam (plane approach) (Figure 1). After sonographic identification of the femoral nerve, 20 mL of 0.5% ropivacaine were administered so it encircled the nerve completely (Figure 2). Afterwards, the patient was placed in ventral decubitus for the sciatic nerve block, which was done using a transversal ultrasound cut of the infragluteal region, 1 cm below the gluteal fold, and the needle was introduced longitudinally to the ultrasound beam (Figure 3). After identifying the sciatic nerve, 20 mL of 0.5% ropivacaine were deposited around it (Figure 4). Ten minutes after the regional blocks, the patient no longer felt pain in the stump and he showed no pin prick sensitivity. The patient was sedated with intravenous propofol (50 µg.kg-1.min-1) during the surgery with no intercurrences. In the recovery room, the patient did not complain of pain and supplementation of analgesia was necessary only 12 hours after the nerve blocks.
Safe and effective neurostimulation and the stimulation of paresthesias require nerve fibers, muscles, and tendons without morphological or functional changes 5. However, prior traumatic amputation of the lower limb at the knee would make it impossible to obtain adequate motor or sensitive responses to the stimulation of the sciatic and femoral nerves. Under direct visualization, it was possible to promote the complete blockade of those nerves and the revision surgery of the stump under light sedation was successful. The use of the ultrasound in brachial plexus blocks for anesthesia has been described in patients with traumatic amputation of the upper limb 6,7. Similarly, its use in the lower limbs for the treatment of chronic neuropathic pain of the amputation stump has been described 4. However, in this patient, femoral and sciatic blocks were done with the intent to anesthetize the remaining limb, which demands a nerve block of better quality than for analgesia.
This case report describes the use of the ultrasound for the successful sciatic-femoral block in which neurostimulation was not feasible and paresthesia was not advisable. Neural damage by chemical, mechanic, or metabolic agents predisposes to the development of progressive nerve lesions in case there is contact between the needle and the nerve (even if they occur in different places) 8. Thus, the contact of the needle with the nerve for neural identification (paresthesia) should be avoided, especially in amputees.
Thus, the use of ultrasound-guided regional block for the treatment of chronic pain and in surgeries of the amputation stump widens the range for the use of peripheral nerve blocks in amputees, promoting high-quality analgesia.
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Correspondence to: Submitted em 7
de janeiro de 2008 *
Received from Hospital Governador Celso Ramos, CET/SBA Integrado de Anestesiologia
da Secretaria de Estado da Saúde de Santa Catarina (SES-SC), Núcleo
de Ensino e Pesquisa em Anestesia Regional (NEPAR), Florianópolis, SC
Dr. Pablo Escovedo Helayel
Av. Governador Irineu Bornhausen, 3440/204 - Agronômica
88025-200 Florianópolis, SC
Accepted para publicação em 20 de maio de 2008
Submitted em 7
de janeiro de 2008
* Received from Hospital Governador Celso Ramos, CET/SBA Integrado de Anestesiologia da Secretaria de Estado da Saúde de Santa Catarina (SES-SC), Núcleo de Ensino e Pesquisa em Anestesia Regional (NEPAR), Florianópolis, SC